Tractor trailers often carry cargos worth tens or even hundreds of thousands of dollars. Additionally the truck driver may be carrying a certain amount of cash for operating expenses and emergency services. This makes him or her an attractive target for robbery which may result in injury or personal loss.
An additional problem is that drivers are required by federal law to take a mandatory rest break after a certain number of hours on the road. This often means that drivers must stop at lonely and secluded spots along the highway, ideal locations for a robbery. In addition to this, vehicle door locks are notoriously insecure in that they can be easily broken, jimmied or picked, leaving the driver exposed to theft, kidnapping and injury.
This invention relates, in general, to a lockdown security device for a tractor tailor, and, in particular, to a device for protecting the driver of a tractor trailer when he or she is taking a rest period by locking the cab of a tractor trailer from the inside so that the doors cannot be opened by people outside the cab.
In the prior art various types of security locking devices have been proposed. For example, U.S. Pat. No. 5,927,107 to Mitchell discloses an extensible rod which can be locked at a particular length in order to prevent unauthorized persons from opening a trunk packed into the hold of a ship or other small room or compartment.
U.S. Pat. No. 5,865,485 to Lawhorne discloses a vehicle door locking system that hooks into the window pockets of a truck door.
U.S. Pat. No. 2,479,096 to Bratz discloses a turnbuckle having a locking device.
Design Patent 346,106 to Walls appears to show a locking device for swinging doors that prevents the doors from swinging inward by clamping onto the door frames and adjusting inward by means of a turnbuckle.
The present invention is directed to an improved locking device for tractor trailers adapted to be hooked over the door handle, pull strap, storage pocket or other part of the door mechanisms on opposite sides of the truck, and tensioned by a shortening mechanism in order to pull the doors towards each other to prevent opening from the outside.
It is an object of the present invention to provide a new and improved door locking mechanism which can be attached to many different door configurations.
It is also an object of the present invention to provide a new and improved door locking mechanism which is quickly disassembled for storage.
It is further an object of the present invention to provide a new and improved door locking mechanism which permits the driver to leave one or both windows of the cab at least partly open without fear that someone could reach in and release the door locking mechanism while the driver sleeps.